Investigation of wear behaviour of TiO2 and Al2O3 reinforced YSZ coating

In this study, three different ceramic powders used as thermal barriers were coated on AISI304 stainless steel by the atmospheric plasma spray method. A pin-on-disc apparatus was utilised to investigate the wear characteristics of the coatings. The effect of wear behavior of the addition of Al2O3 and titanium dioxide (TiO2) into the YSZ coating was investigated. Before the wear test, sanding and polishing processes were carried out to ensure that the average surface roughness of the coatings was less than 0.8 µm. The wear test according to ASTM G99-04, was conducted on a pin-on-disc device at a speed of 143 rpm. The test was performed in a dry condition, with a minimum of 8000 cycles. The wear test utilised a 4N load and 6 mm-diameter Al2O3 balls. The surface properties and wear characteristics of the coatings were analysed using a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) after conducting coating and wear tests. The wear rate of the samples was assessed using optical profilometry. A micro Vickers test equipment was employed to assess the microhardness of the materials. The findings demonstrated that the inclusion of Al2O3 in YSZ led to an enhancement in wear resistance, but the incorporation of TiO2 resulted in a notable reduction in wear resistance.